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Golden Gate Club Connectivity

Golden Gate Club Connectivity. Studies of Wireless Networks with Realistic Physical Layer Emulation: The ORBIT Test-Bed Facility Funded by NSF NRT project #ANI-0335244 and DARPA IPTO. Rutgers, The State University of New Jersey www.winlab.rutgers.edu Contact: Prof. D. Raychaudhuri

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Golden Gate Club Connectivity

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  1. Golden Gate Club Connectivity

  2. Studies of Wireless Networks with Realistic Physical Layer Emulation: The ORBIT Test-Bed FacilityFunded by NSF NRT project #ANI-0335244 and DARPA IPTO Rutgers, The State University of New Jersey www.winlab.rutgers.edu Contact: Prof. D. Raychaudhuri ray@winlab.rutgers.edu PnP Networks www.pnphome.com Contact: Richard E. Howard reh@pnphome.com

  3. Modeling Wireless Networks:The Radio Problem • Ethernet Modeling: • All nodes in a subnet receive all packets • Low error rate • Emphasis on collision, routing, congestion, ... • Wireless Network Modeling • Packet reception depends on complex, changing RF conditions • Hidden nodes and range of link qualities • Hard to model—non-local, sensitive dependence on environment • Computationally intractable—”Hall of Mirrors” • Extra control “knobs”—transmit power, channel, packet length, ... • High error rates under the best conditions • Conventional network modeling must be done after getting RF right.

  4. Blocked Mission Traffic--Weighted Fraction (BloMiT-WeFra) 0. 1% 1% 10% 100% Legend Perfect control Cognitive control (CogCon) Static configuration (SOA) Reconfigure network, power/rate management, delay low priority data. A Reconfigure network, power/rate management, send buffered data. Localized bursty radio interference B Localized bursty radio interference 200 MPU leave Sector M —local capacity excess 100 MPU added in Sector C —local overload 100 MPU added in Sector C —local overload Adjust fragmentation threshold, manage power/data rate. C H-Hour B C2 C1 A1 Midway A2 BloMiT-WeFra Waterloo Mission Time (mtime)

  5. ORBIT: Testbed Overview • ORBIT consists of radio grid emulator + field trial network • Emulator used for detailed protocol evaluations in reproducible complex radio environments • Field trial network for further real-world evaluation & application trials Global Internet ns-2+ scripts & code downloads Research User of Testbed Static radio node Emulator Mapping Firewall High Speed Net Mobility Server “Open” API 3G BTS 3Gaccess link “Open” API Access Point (802.11b) Ad-hoc link Wired routers Radio link emulation End-user devices Dual-mode Radio device Mobile node (robotic control) 1. Radio Grid for Lab Emulation 2. Field Trial Network

  6. ORBIT: Testbed Facilities • Simulation (Cluster) • Compute facility to run simulations (NS) • Create extensions to ns-2 PHY modules for improved realism and cross-layer • Emulation Grid • 802.11a radio nodes (~20x20 @ 1m spacing) • Mapping of various “typical” wireless net scenarios • Open API for complete flexibility of OS/protocol software; Linux libraries • Field Trial System • Outdoor system for greater realism in protocol testing & for application development, live demos, etc. • 3G base station router with IP interface • ~50 open API 802.11a AP’s covering RU NB campus, some downtown areas… • Mobile AP’s on buses, etc.

  7. ORBIT: Physical Facilities • ~12,000 sq ft (Grid + Lab. space + Offices) • Rt 1 South @ TechnologyCenter of NJ • “Move in” late 2004

  8. ORBIT: Radio Grid Scenarios • Use programmable, controlled interference in a physically small environment. • An n x m array of identical radios on grid. • A secondary array of programmable interferers • Mapping algorithm which matches “real-world” SNR vectors to selected nodes on grid, using some nodes as interferers

  9. ORBIT: Field Trial System

  10. Interference Measurements Using ORBIT Testbed 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 Walls ~1.5m ~1m ~4m Link Nodes Interfering Nodes ~3m ~5m

  11. Packet Loss as a Function of Channel SpacingFor Different Packet Payload Sizes 256 B; 1.0 Mb/sec 512 B; 1.9 Mb/sec 768 B; 2.9 Mb/sec 1024 B; 3.9 Mb/sec 1280 B; 4.8 Mb/sec 1 0.9 0.8 0.7 Packet Payload; Offered Load 0.6 0.5 Fraction of Dropped Packets 0.4 0.3 0.2 0.1 0 1 2 3 4 5 Channel Spacing from Interferer PnP-20040524 One sender, 1 receiver, 3 interferers 1 microsecond packet spacing set

  12. 256 B; 0.67 Mb/sec 512 B; 1.35 Mb/sec 768 B; 2.0 Mb/sec 1024 B; 2.7 Mb/sec 1280 B; 3.4 Mb/sec Packet Loss as a Function of Channel SpacingFor Different Packet Sizes at 1/3 Lower Rate 1 0.9 0.8 0.7 Packet Payload; Offered Load 0.6 0.5 Fraction of Dropped Packets 0.4 0.3 0.2 0.1 0 1 2 3 4 5 Channel Spacing from Interferer PnP-20040526 One sender, 1 receiver, 3 interferers 100 microsecond packet spacing set, 1 mW

  13. Packet Loss as a Function of ThroughputFor Different Channel Spacings Same 1 2 3 4 5 1 0.9 0.8 0.7 0.6 Channel Spacing Fraction of Dropped Packets 0.5 0.4 0.3 0.2 0.1 0 0 0.5 1 1.5 2 2.5 3 3.5 Net Throughput (Mb/sec) PnP-20040526 One sender, 1 receiver, 3 interferers

  14. High Power Increases Channel Overlap FN Near Sending Nodes Receiving Nodes Far FN

  15. Optimizing Wireless Networks FN Net A Ch 1 Requires Knowledge of Application Behavior Greatest Improvement Video subnet optimized for QOS Ch 2 Ch 5 Ch 10 Video Data Adjacent Channel Interference Both networks have reduced capacity Net B Partition Network Based on Application Requirements

  16. Network States (Measured)

  17. Integrated Mission IT Metrics--Static Path Through Mission

  18. Integrated Mission IT Metrics--Optimized Path Through Mission Improvement potential for this mission profile BloMiT-WeFr: 1,578 => 182 Mission Traffic: 14 GB => 62 GB Note: This is wireless link-layer characterization only. Guaranteed delivery protocol (e.g. TCP) would add “thrashing” and increase the difference.

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